Cable restrained reciprocating blade system for energy extraction from moving body of water

Abstract

A cable restrained reciprocating blade system is adapted for extracting energy from a moving body of water to facilitate conversion to electric energy. In an exemplary embodiment, the system includes a blade placed in a moving body of water and having a hydrofoil configuration adapting it to undergo lateral movement in response to contact with the moving body of water, a control cable attached to an upstream end of the blade and applying a condition of tension to the blade, a pair of power cables attached at first ends to a downstream end of the blade and extending in generally transverse relationship to the direction of flow of the moving body of water and in opposite directions from blade, and a load mechanism connected to second ends of the power cables for alternately applying conditions of tension and slack thereto so as to orient the blade at an angle of attack that causes the blade to undergo lateral movement through an oscillatory path extending generally transverse to the direction of flow of the moving body of water and thereby extract energy from the moving body of water. The load mechanism also is operable to cause the blade upon reaching the respective opposite ends of the oscillatory path to reverse the orientation of the angle of attack of the blade relative to the given flow direction so that the blade will then respond to the moving body of water and initiate movement in the opposite direction along the oscillatory path.

I claim: 
     
       1. A reciprocating blade system for energy extraction from a moving body of water, said system comprising: (a) at least one blade for placement in a moving body of water flowing in a given flow direction, said blade having a hydrofoil configuration capable of being oriented at an angle of attack relative to the given flow direction to cause said blade to undergo lateral movement in response to contact with the moving body of water;   (b) control means attached to an upstream end of said blade with reference to the given flow direction for applying a condition of tension thereto;   (c) power means for transmitting conditions of tension and slack, said power means being attached to a downstream end of said blade with reference to the given flow direction and extending in generally transverse relationship to the given flow direction and in opposite directions from said blade; and   (d) load means attached to said power means and being operable for alternately applying conditions of tension and slack through said power means to said blade so as to cause said blade, depending upon the orientation of said angle of attack of said blade to the given flow direction, to respond to the moving body of water and undergo lateral movement through one at a time of a pair of opposite directions along an oscillatory path extending in generally transverse relationship to the given flow direction and thereby extract energy from the moving body of water, said load means also operable to cause said blade upon reaching respective opposite ends of the oscillatory path to reverse the orientation of the angle of attack of said blade relative to the given flow direction so that said blade will then respond to the moving body of water and initiate movement in the opposite direction along the oscillatory path.   
     
     
       2. The system of claim 1 wherein said blade includes an upright extending blade member having respective upper and lower portions, each of said upper and lower portions having upper and lower parts being reversely canted relative to the vertical. 
     
     
       3. The system of claim 1 wherein said blade includes: an upright blade member having respective upper and lower portions; and   a plurality of rudder members each attached to and extending downstream from a respective one of said upper and lower portions of said blade member at upper and lower locations thereon substantially equally spaced in opposite directions from a midpoint on said blade member located being equidistantly from opposite upper and lower ends of said blade member.   
     
     
       4. The system of claim 3 wherein said control means includes a plurality of control cables attached at first ends to said upper and lower locations on said upstream end of said blade member and extending upstream therefrom with reference to the given flow direction. 
     
     
       5. The system of claim 4 wherein said control means also includes a plurality of shrouds each extending along opposite sides of and surrounding one of said control cables. 
     
     
       6. The system of claim 1 wherein said control means includes an elongated control cable attached at a first end to said upstream end of said blade and extending upstream therefrom with reference to the given flow direction. 
     
     
       7. The system of claim 6 wherein said control means also includes a stationary structure spaced upstream from said blade, said control cable at a second end opposite from said first end being attached to said stationary structure and extending therefrom to said upstream end of said blade for applying the condition of tension from said stationary structure through said control cable to said upstream end of said blade. 
     
     
       8. The system of claim 1 wherein said power means includes a pair of elongated power cables each having a first end attached to said downstream end of said blade and extending in generally transverse relationship to the given direction and in opposite directions from said blade to second ends opposite from said first ends of said power cables. 
     
     
       9. The system of claim 8 wherein said power means also includes a plurality of pulleys mounted at stationary locations spaced in opposite directions from said blade and disposed between said blade and said load means, each of said pulleys having a respective one of said power cables received and entrained at least partially thereabout. 
     
     
       10. The system of claim 1 wherein said load means includes at least one hydraulic circuit having a pair of circuit portions, one of said circuit portions providing an output for delivering a pressurized flow of fluid from the circuit to an external energy conversion mechanism, the other of said circuit portions providing an input for returning a pressurized flow of fluid from the external energy conversion mechanism back to said circuit. 
     
     
       11. The system of claim 10 wherein said load means also includes a hydraulic actuator reciprocally movable through a working cycle and being connected to said hydraulic circuit, said hydraulic actuator having opposite ends connected to said power means and being operable for alternately applying conditions of tension and slack thereto as said hydraulic actuator is reciprocally moved through said working cycle by said lateral movement of said blade along the oscillatory path. 
     
     
       12. The system of claim 1 wherein said said load means is adapted to operate through a working cycle and to be coupled to an external energy conversion mechanism which is adapted to operate through an energy conversion cycle in response to operation of said load means through said working cycle such that lateral movement of said blade causes said load means in conjunction with the energy conversion mechanism to convert the extracted energy to another form of energy. 
     
     
       13. The system of claim 1 wherein said load means also is connected to said control means to control the condition of tension in said control means as a function of the position of said blade along its oscillatory path. 
     
     
       14. The system of claim 13 further comprising: at least one pulley mounted at stationary location between said blade and said load means and adapted to receive and entrain said control means at least partially thereabout and extending therefrom to said load means.   
     
     
       15. The system of claim 1 wherein said load means also is connected to said power means to control the condition of tension in said power means as a function of the position of said blade along its oscillatory path. 
     
     
       16. A reciprocating blade system for energy extraction from a moving body of water, said system comprising: (a) at least one blade for placement in a moving body of water flowing in a given flow direction, said blade having a hydrofoil configuration capable of being oriented at an angle of attack relative to the given flow direction to cause said blade to undergo lateral movement in response to contact with the moving body of water;   (b) an elongated control cable attached at a first end to an upstream end of said blade with reference to the given flow direction;   (c) a stationary structure spaced upstream from said blade, said control cable at a second end opposite from said first end being attached to said stationary structure and extending therefrom to said upstream end of said blade for applying a condition of tension from said stationary structure through said control cable to said upstream end of said blade;   (d) a pair of elongated power cables for transmitting conditions of tension and slack, each said power cable having a first end attached to said downstream end of said blade and extending in generally transverse relationship to the given direction and in opposite directions from said blade to second ends opposite from said first ends of said power cables; and   (e) load means attached to said second ends of said power cables and being operable for alternately applying conditions of tension and slack through said power cables to said blade so as to cause said blade, depending upon the orientation of said angle of attack of said blade to the given flow direction, to respond to the moving body of water and undergo lateral movement through one at a time of a pair of opposite directions along an oscillatory path extending in generally transverse relationship to the given flow direction and thereby extract energy from the moving body of water, said load means also operable to cause said blade upon reaching respective opposite ends of the oscillatory path to reverse the orientation of the angle of attack of said blade relative to the given flow direction so that said blade will then respond to the moving body of water and initiate movement in the opposite direction along the oscillatory path.   
     
     
       17. The system of claim 16 wherein said blade include: an upright blade member having respective upper and lower portions; and   a plurality of rudder members each attached to and extending downstream from a respective one of said upper and lower portions of said blade member at upper and lower locations thereon substantially equally spaced in opposite directions from a midpoint on said blade member located being equidistantly from opposite upper and lower ends of said blade member.   
     
     
       18. The system of claim 16 further comprising: a shroud extending along opposite sides of and surrounding said control cable.   
     
     
       19. The system of claim 16 further comprising: a plurality of pulleys mounted at stationary locations spaced in opposite directions from said blade and disposed between said blade and said load means, each of said pulleys having a respective one of said power cables received and entrained at least partially thereabout and extending therefrom to said load means.   
     
     
       20. The system of claim 16 wherein said load means includes at least one hydraulic circuit having a pair of circuit portions, one of said circuit portions providing an output for delivering a pressurized flow of fluid from the circuit to an external energy conversion mechanism, the other of said circuit portions providing an input for returning a pressurized flow of fluid from the external energy conversion mechanism back to said circuit. 
     
     
       21. The system of claim 20 wherein said load means also includes a hydraulic actuator reciprocally movable through a working cycle and being connected to said hydraulic circuit, said hydraulic actuator having opposite ends connected to said power means and being operable for alternately applying conditions of tension and slack thereto as said hydraulic actuator is reciprocally moved through said working cycle by said lateral movement of said blade along the oscillatory path. 
     
     
       22. A reciprocating blade system for energy extraction from a moving body of water, said system comprising: (a) a plurality of blades for placement in a laterally spaced apart relationship to one another in a moving body of water flowing in a given flow direction, each of said blades having a hydrofoil configuration capable of being oriented at an angle of attack relative to the given flow direction to cause said each blade to undergo lateral movement in response to contact with the moving body of water;   (b) a plurality of elongated inelastic flexible control cables each attached at a first end to an upstream end of one of said blades with reference to the given flow direction;   (c) a stationary structure spaced upstream from said blades, said control cables at second ends opposite from said first ends thereof being attached to said stationary structure and extending therefrom to said respective upstream ends of said blades for applying a condition of tension from said stationary structure through said control cables to said upstream ends of said blades;   (d) power means for transmitting conditions of tension and slack, said power means being attached to downstream ends of said blades with reference to the given flow direction and extending in generally transverse relationship to the given flow direction and in opposite directions from said blades; and   (e) load means attached to said power means and being operable for alternately applying conditions of tension and slack through said power means to said blades so as to cause said blades, depending upon the orientation of said angle of attack of each of said blades to the given flow direction, to respond to the moving body of water and undergo lateral movement through one at a time of a pair of opposite directions along an oscillatory path extending in generally transverse relationship to the given flow direction and thereby extract energy from the moving body of water, said load means also operable to cause said blade upon reaching respective opposite ends of the oscillatory path to reverse the orientation of the angle of attack of said blade relative to the given flow direction so that said blade will then respond to the moving body of water and initiate movement in the opposite direction along the oscillatory path.   
     
     
       23. The system of claim 22 wherein said load means includes: at least one hydraulic circuit having a pair of circuit portions, one of said circuit portions providing an output for delivering a pressurized flow of fluid from the circuit to an external energy conversion mechanism, the other of said circuit portions providing an input for returning a pressurized flow of fluid from the external energy conversion mechanism back to said circuit; and   at least one hydraulic actuator reciprocally movable through a working cycle and being connected to said hydraulic circuit, said hydraulic actuator having opposite ends connected to said power means and being operable for alternately applying conditions of tension and slack thereto as said hydraulic actuator is reciprocally moved through said working cycle by said lateral movement of said blade along the oscillatory path.